The various functional performances of living organisms (human beings, animals, plants) are usually not diffused over their bodies, but rather are separate and are concentrated according to a characteristic structural and functional plan for each individual type of function taking place in a distinct biological part. These biological parts, the subject of the invention, include organelles, cells, tissue, organs, and parts thereof. Frequently these parts are then combined into complex systems to which the invention likewise makes reference. Examples of such biological parts are muscle tissue, cartilage, bone, liver, spleen, skin, etc. Examples of complex systems are the nervous system, vascular system, skeletal system, hormone system, immune system, etc.
In the course of life and likewise in the formation of the living organism, any living being can be subject to damages of structure and function of individual biological parts up to the point that the part or even the entire system can be completely nonfunctional. This functional failure could among other things be of genetic origin or it could occur because microorganisms such as bacteria, viruses, funguses or parasites have damaged or destroyed the biological parts, because injuries have occurred due to mechanical, chemical, thermal, electric or radiological effects, or because disorders of unknown origin have had an effect on the biological parts in the form of various degenerative processes, cancer or many types of modifications due to age.
The present state of the art is to try to compensate for damages or even for complete loss of function of individual biological parts by application of chemical compounds. In doing so, a deficiency of function or the complete lack of function or functional effectiveness of individual metabolic products which are produced by the relevant biological part is to be compensated. One example of this is the loss of the function or some part of the function of the pancreas, which leads to an insulin deficiency or to a complete failure of the product synthesis of the pancreas. Insulin obtained from animals or produced chemically or biotechnically is used to compensate for the deficiency. This manner of use of chemical compounds or biological synthesis products can only partially compensate for the insufficient performance of functions of biological parts, because only short-term effective deposits of the compound can be placed in the body and there is no regulated release of the materials or synthetic materials into the body to fulfill the instant requirement of the body.
Because of these problems, and especially in the case of the occurrence of damages to a plurality of functional parts or in the case of destruction of an entire biological part, the state of the art also includes the integration of the often life-vital defective or lost functional parts into a technical apparatus and to attach the apparatus to the body or to build it into the body as a prosthesis. Some examples of such auxiliary means in extracorporal use are spectacles, hearing aids, arm or leg prostheses, synthetic kidneys, etc. For intracorporal use, heart pacemakers, blood vessel prostheses, synthetic joints, etc., are known. There are also mixed extra/intracorporal auxiliary parts, such as tooth implants, but ready-to-use prostheses for intracorporal replacement of inner organs such as the artificial heart, artificial pancreas, artificial liver or kidneys, do not yet belong to the state of the art. Basically, a technical replacement for biological parts still remains to be secured, while only partial functions can be replaced and the entire functional performance of such replaced biological parts can never be secured. In addition, the functional capacity of the technical system, in other words, of the prostheses or the artificial organ, cannot be guaranteed over a long period, and its adaptation to changing conditions is not possible as it is with a true biological part. In addition, there are significant acceptance problems, in terms of the tolerance of a foreign body in the organism and also the feeling of dependence on the function of a technical apparatus.
Furthermore, the transplantation of biological parts belongs to the state of the art. In transplantation, a transfer of biological parts within the same organism (autogenic transplantation), a transfer from a donor of the same type as the receiver to said receiver (allogenic transplantation) or a transfer from a donor of a different species from the receiver to said receiver (xenogeneic transplantation) are known.
The possibilities revealed by autogenic transplantation are for the most part limited by the availability of biological parts for a transfer. However, as far as is possible, it is the preferred usage, since it causes no immunological problems. Examples of this transplantation include skin transplants, the autotransfusion of blood, transplantation of muscles, fat tissue, bone, cartilage, blood vessels, etc.
Because of availability, the preferred transplantation is allogenic transplantation. In this field, despite many problems involved with them, blood transfusions have succeeded in a wide range of uses, and in addition to blood banks which have been established for this purpose, now there are also skin and bone banks. Numerous other organs are likewise transplanted allogenically, such as, for instance, kidneys, hearts, livers, pancreases, bone marrow, corneas, etc.
In the case of allogenic and xenogenic transplantation of biological parts however, the problem arises of immunological incompatibility, which leads to rejection by the living organism with respect to the transplant and for the most part constrains the receiver to lifelong intake of immunosuppressive substances with concurrent damaging side effects. Also, there is the continuing danger of transmission of illnesses, since the "living" biological parts cannot be sterilized. With allogenic transplantation therefore the genetic uniformity of the receiver is lost, and the transplantation itself actually becomes chimeric.